Safety-valve



- SAFETY VALVE. I rim-272.926. Patented Peb.27, 1883.

F/Gi r/az V/fnwses fiuienfof.

NITED STATES HENRY C. WILDER, OF ASHBY, MASSACHUSETTS.

SAFETY- VALVE.

SPECIFICATION forming part of Letters Patent No. 272,926, dated February 27, 1883.

Application filed July To all whom at may concern:

Be it known that I, HENRY G. WILDER, a citizen of the United States, residing at Ashby, in the county of Middlesex and State of Massachusetts, have inventeda new and useful Safety-Valve, of which the following is aspecification.

Myinvention relates to improvements in that class of safety-valves in which the relief-valve is intended to discharge with its full capacity while disengaged with its seat and the objects of my improvements are, first, to construct avalve which shall automatically operate so as to relieve steam-boilers or other reservoirs without greatly reducing the pressure below that to which the valve is adjusted; second, to inclose the screw by which the adjustment is effected in such a manner that when sealed it cannot be readily tampered with; third, to provide a seal upon which may be stamped or otherwise marked a duplicate record of the manufacturers or inspectors adjustment; fourth, to provide adj usting facilities by which the trip-lever can be placed on that side of the valve most easy of access; and,fifth, to approach simplicity of construction and symmetry of outline by arranging most of the essential parts on one concentric line. I attain these objects'by the mechanism illustrated in the accompanying drawings, in which- Figure l is a side elevation; Fig. 2, a central vertical section of the entire valve, and Fig. 3 an enlarged perspective view of the balanced annular and relief valves connected.

Similar letters refer to similar parts throughout the several views.

The base-chamber A A is provided with the inlet-passage B and the discharge-passage 0, each having a thread or other means by which proper connections can be effected. The discharge-passage G is partly inclosed within the base-chamber A A in such a manner that its communication with the interior of the basechamber A A is only effected by the reliefvalve D. The balanced annular piston E is joined to the relief-valve D by arms or equivalent connections, and is loosely fitted between the case F and the disk G. 7 By this arrangement the balanced annular piston E and disk G, in addition to their functions hereinafter described, separate the balancing-chamber H 19, 1882. (No model.)

H from the base-chamber A A, and by the loosely-fitting parts the pressure in the basechamber A A is communicatedto the balancing-chamber H H.

J is the escape-valve, provided with the disk G, the spindle K, the spring L, and the adjusting-screw M, by which the adjustment to a given pressure is effected.

I is the seat which limits the upward movement of the balanced annular piston E.

N is the binding-nut, provided with the protecting-cap 0 to prevent free access to the adjusting-screw M.

P is the lever arranged beneath the button Q, by which the valves may be frequently operated to prevent adhesion.

B is the coupling-nut, which holds the springcase S in position by its bearing on the flange T. By this arrangement the trip-lever P is adjustable to different positions around the base-chamber A A.

U is the seal, embedded or otherwise secured between the bindingnut N and the springcase S, and may be made any convenient size and form, of lead or other material which cannot be removed without dei'acement. By this arrangement the binding-nut N cannot be removed without tirst removing the seal U.

The normal pressure in the balancing-chamber H H is equal with that in the base-chamber A A; but when the pressure is suflicient to compress the spring L and open the escapevalve J the pressure in the balancing-chamber H H becomes less than the pressure in the base-chamber A A, so that the balanced annular piston E closes with its seat I, thereby opening the relief-valve D until the pressure in the base-chamber A A, acting on the disk G, is reduced so that the spring L closes the escape-valve J and the pressure in the balancing-chamber H H again becomes normal, thereby releasing the balanced annular piston E from its seat I, when the pressure in the base-chamber A A closes the reliefvalve D.

I am aware that previous to my invention safety-valves have been made with escapevalves provided with a disk and base-chamber having a relief-valve. I therefore do not claim any of these things, broadly; but

What I do claim as my invention, and desire to secure by Letters Patent, is-- 1. In a safety-valve, the combination, with a relief-valve and an annular piston, of an escape-valve so arranged that when the pressure is relieved from one side of the annular piston the relief-valve is opened, substantially as shown and described.

2. In asafety-valve, the combination, with a relief-valve, ot' the balanced annular piston surrounding a disk connected with an escapevalve, and so arranged that when the escapevalve is opened the pressure is relieved from one side of the annular piston, thereby opening the relief-valve, substantially as shown and described.

3. In a safety-valve, the combination, with a balancing-chamber provided with an escape- 

